First off I have a 1998 A6.

Okay so for the past little while I've been deciding what I'm going to do with my audio.

I'm going all aftermarket and intend to run new wires and such and just leave everything that is stock how it is (except the various components obvoiusly) then when I sell the car revert back to stock.

First thing I'll install is the new HU. Alpine CDA-9856. The last time I installed a head unit was on my 73 volvo probably 5 years ago, so I'm a little worried about knowing what to do.
I bought <a href="http://www.techronics.com/index.cfm?fuseaction=product.display&Product_ID=22 34">this installation kit</a> but wasn't quite sure what to do about the wiring. All my equiptment should get here on monday so I have the weekend to figure it out

After the install of the HU I'm going to run 2 amps on a custom rack that I've built in the trunk. 1 powering a 12" sub that will eventually get a custom enclosure where the stock amp currently lives. And the other will power the 4 speakers. I'm also a little nervous about installing the amps just cause it deals with direct power to the battery and things like a distro block, fuses, etc, but with the internet and it's general installation guides I think I can figure it out.

Anyway enough of my rambling. Does anyone know if I need to buy a harness or what I need to do to hook up the HU?

I appreciate your help!

 

But you'll need to swap over the perm live and ignition on live as Audi wire them the wrong way round.
All the other wiring will be redundant as you're doing the job properly and by passing all the Audi garbage.
You'll need an antenna amp for the head unit and a fascia panel. Everything else will be industry standard (RCA's for the amps, wiring for the amps). Personally I'd just run one fused power cable from the battery, either into a fused distribution block, or into the first amp and daisychain to the second amp.

 

Thanks for the direction. But I'm a bit of a newbie here so:

a: swap the perm live and ignition on live

I think I understand what you're talking about, but a bit more specific might help

b: an antenna amp for the head unit and a fascia panel
Antenna amp? Fascia panel?
I read that I need an adapter for the antenna but since I forgot about it when I bought everything else I didn't worry about it since I never listen to the radio in my car. I figured i'll get around to it when i get around to it.

As for the amp installation, I figured I'd run 1 fused cable to the trunk into a distrobution block. What was confusing to me was what stuff to get. I don't know where I can just buy the cable or the distrobution block around town. All I see is dual amp install kits that cost 100+ and I just want the parts. Some of them come with all sorts of gadgets that I'm not sure I need and whatnot.

Also I didn't know what gauge and fuse sizes to get. I figured 4 to the block and 8 to the amp. But I'm just rambling again. I guess I'm excited to get everything done, but nervous that i'll probably jack something up in the process.

By the way, the amp rack is coming along swimmingly and one day down the road I will be building <a href="http://a4mods.com/index.php?page=webcontent/pages/subbox.html">this sub enclosure</a> (just on the other side of the trunk.)

Once again, thanks for the help!

 

The power connector used in all Audi's is actually a standard black ISO connector so will plug directly into pretty much any aftermarket HU.
Most head units use a 12v perm live feed that is on all the time to retain all your presets, clock etc, and an ignition on live so that the HU switches off when you take the keys out, and on when you start the engine.
Aud wire these up the wrong way round to the industry standard, so while the HU will work no problem, as soon as you take the keys out it will lose all your presets. All you need to do is swap the yellow &amp; red wires on the aftermarket HU.
The fascia adapters are bits of plastic that hide the gaps either side of the new HU, as Audi HU's have an extra wide face plate.
Very few installs actually need 4 gauge cable. Unless your running in excess of 1KW then 8 guage will be fine.

 

Awesome! Thanks!

 

Thanks for the help, but when I pulled out the concert Head Unit the wiring certainly doesn't fit the Alpine unit.

Since I have to install this tomorrow (or today as it may be, aka thursday) and I want to keep the stock wiring harness, I figured I'd cut the wires and use bullet connecters to connect the alpine and so I can reconnect the stock setup later.

The problem I have is I'm not sure which wires I need to connect to the alpine.
Here is the Alpine wiring diagram:
<img src="http://gid.rata.com/images/alpineHU.gif">
The wires I need to connect are:
5: Illumination
6: Switched Power (ignition) lead
7: Battery Lead
8: Ground

Your help would be GREATLY appreciated!

And here is a sketch of the diagram on the concert HU:
<img src="http://gid.rata.com/images/concert.gif">

My guess is the + is battery, - is ground, -o/ o- is the ignition and i have no idea on the illumination.

Thanks again!

 

The Concert uses a straight ISO power connector. Are you saying the Alpine doesn't have a standard ISO power connector? All the Alpine HU's I've ever installed do.
The front speakers are also straight plug &amp; play.
+ is perm live
s is ignition live
- is ground
The little "sun" symbol is illumination

The long connector (shown at the bottom) is largely irrelevant, but you'll need to use an RCA input adapter to take the RCA's from the Alpine into the rear amp. The big red plug is irrelevant as it is for satnav &amp; phone kit.
So you only need to worry about the black ISO power harness, and the brown front speaker loom.

 

Hi Gidgidonihah,
How did you go? I'm installing a CDA-9857 in my 2000 TTR (Concert 1) with the factory amplified Bose system. Wiring is exactly the same as that for 9856. Do you use a wiring harness. I plan to use the Metra wiring harness 70-1787.
FYI, it was suggested to me that one should install a GLI (ground loop isolator) inline with the front and rear connections from the HU to the Bose amp to eliminate the noise when you switch off/on the HU.
I'm from Sydney, Australia and I'm tracking your experience very closely.
FYI, my email is lito_saulo@bigfoot.com.